Re: fix TCP roundtrip time update code

From: Nivedita Singhvi (
Date: Wed Jun 04 2003 - 01:04:02 EST

David Mosberger wrote:

> $ httperf --rate 1000 --num-conns 1000000 --verbose --hog --server HOST \
> --uri pathto30KBfile

Hmm, ditto, except I was way down at --rate 300 (was seeing client
errors of fd-unavail). Have ulimited upwards but am still seeing

> on 3 clients (for a total of 3000 conns/sec). You can't go higher
> than 1000 conn/sec per client (IP address) because otherwise you run
> out of port space (due to TIME_WAIT).

You can hike /proc/sys/net/ipv4/tcp_tw_recycle for that.

> This load worked well for a machine with a single GigE card. All
> network tunables were on the default setting (in particular, the tx
> queue len was 300, which is were the losses came from).
> With this load, I saw bad RTT values in the route cache within a
> couple of seconds after starting the third httperf generator. It then
> took a bit longer (on the order of 1-2 minutes) until the first
> TCPAbortFailed errors started to pop up

I saw a few AbortOnTimeouts, but no AbortFailed counts.

Those should be TCPAbortOnTimeout counts, rather than TCPAbortFailed
errors, I would expect? Why AbortFailed? Coming from IP via


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